Use these approximately 70 records to derive ratios of mean measured, A0, to predicted PGA, Ae,
log(A0∕Ae), and for ratios of mean horizontal to vertical PGA, logAh∕Av, for each type of faulting. Use
every earthquake with equal weight independent of number of records for each earthquake.

Results are:

Category 1

Category 2

Category 3

Category 4

Category 5

logA0∕Ae

0.35 ± 0.13 (16)

0.11 ± 0.17 (5)

0.22 ± 0.08 (17)

0.06 ± 0.13 (6)

-0.06 ± 0.20 (9)

logAh∕Av

0.32 ± 0.13 (12)

0.32 ± 0.08 (5)

0.27 ± 0.07 (12)

0.18 ± 0.10 (5)

0.17 ± 0.11 (5)

where ± gives 0.7 confidence intervals and number in brackets is number of earthquakes used.

Also calculate mean envelope increasing speed for P-wave amplitudes, A, obtained at teleseismic distances:
n = dlnA∕dt, where t is time for P-wave arrival and try to relate to ratios for each type of faulting.